Drawing can be loosely defined as mark-making on a flat surface. Usually, the mark-making device is a pencil and the flat surface is a sheet of paper, but many other combinations of tools and surfaces are possible. As such, sometimes it is hard to categorize a work as drawing as opposed to some other kind of art, such as painting, printmaking, digital media, or sculpture, which often incorporate mark making.

Learning to draw is considered fundamental to learning to produce other forms of visual art. Not only are the skills acquired through drawing useful, but a sketch is frequently the first step in producing new artwork. Drawing is also popular because the necessary materials are cheap and widely available and because the drawing process is fast, direct, and can be done almost anywhere. Drawing is also very revealing as to an artist's ability - his or her understanding of form, grasp of visual poetry, and artistic vision. Master drawings are exquisite, breathtaking, and tell us more about the mind of the artist than a highly polished, fully rendered painting.

When most people think about drawing tools, they think of the ordinary "number two" pencil, most likely a yellow, hexagonal one, with a pink eraser on the end. Pencils come in many different styles, however.

The marking core of the pencil is called the "lead", although these days it doesn't contain any actual lead. Most pencils contain graphite -- a silvery-gray form of carbon -- as their pigment, although other pigments such as charcoal or various colors are possible.

Graphite leads are rated in relative hardness. On one side of the scale is "9H", which is the hardest grade of pencil. On the other side of the scale is "9B", which is the softest ("blackest") grade of pencil. In the middle of the scale is the "HB" pencil, which corresponds to the standard "number two" pencil. The "F" grade of pencil is a bit harder than "HB". Hardness is not necessarily consistent between brands of pencils; experiment to find a hardness that you feel comfortable with.

Hard lead qualities:

Capable of very light strokes.

Stays sharp longer.

More likely to tear through paper.

Brittle -- tends to break under pressure.

Soft lead qualities:

Gives the darkest strokes.

Dulls quickly.

Soft -- tends to crumble under pressure.

Graphite is by nature somewhat brittle; care must be taken not to drop pencils or leads or the lead might break, even within a wood casing.

Pencil leads can be packaged in different ways. The typical packaging is in a wooden casing, which requires a pencil sharpener or a knife to expose the pencil lead for drawing. It is also possible to buy solid graphite sticks, usually wrapped in plastic, which can be used to make strong, bold marks on the page. Mechanical pencils use metal or plastic device instead of a casing, feeding out a thin lead. Lead holders can be thought of a hybrid between mechanical and traditional pencils, since they replace the wooden casing like mechanical pencils but also hold a lead of a thickness comparable to traditional pencils.

A property of mechanical pencils is that their thin leads produce a very even line, unlike thick-leaded pencils, which produce lines whose width varies slightly with pressure, allowing for more expressive linework. Another property of thick-leaded pencils is that they can be applied to the paper at a sharp angle to quickly apply graphite in a thick shading stroke. These properties tend to make mechanical pencils more desirable for precise drafting work and thick-leaded pencils more desirable for expressive drawing.

Colored pencils contain a pigment instead of graphite. The binding material of colored pencil leads varies among brands, leading to different degrees of waxiness or blendability. Watercolor pencils, a relatively recent development, use a water-soluble binding material which allows the artist to blend colors by brushing water over the artwork. A special variety of blue pencil -- "non-repro" blue -- does not photocopy well; comic book artists typically use these pencils to lay out their artwork before tracing over it with regular graphite pencils.

Charcoal and conté pencils are simply pencils that contain a charcoal or conté crayon core instead of a graphite one. See their respective sections below.

Grease pencils use a soft wax as a binding agent, wrapped in a rolled paper casing that is peeled away to expose the core. Since they use wax as a binding agent, these pencils are similar to crayons. They produce a bold, dark line which cannot be erased from paper. They can also produce a temporary line on smooth surfaces that can be wiped away with a solvent; this makes them useful for marking glass or plastic before cutting, for example.

Pencils with wooden casings can come in a variety of shapes, including round or hexagonal. Oblong or oval casings are also available, which some people find easier to hold and sketch with. On one hand, they offer both thick and thin surfaces for mark-making. On the other hand, they don't work in pencil sharpeners and must thus be sharpened with a knife.

For sharpening wood-cased pencils, a variety of mechanical solutions are available, from small, one-piece metal sharpeners, to hand-cranked sharpeners, to electric sharpeners. An alternative to mechanical sharpening is to whittle the wood casing away with a pocket knife; although this gives an irregular shape to the lead, it allows you to choose as sharp or wide an angle of lead as you want. Once the pencil is sharpened, some artists prefer to keep it sharp by shaping the point against a piece of scrap paper or sandpaper. Some art stores sell little pads of sandpaper for this purpose.

Charcoal is a popular artist's tool because it produces an inky, matte black and can be easily manipulated with the fingers or other smudge tool. Charcoal work tends to smear more easily than graphite work and usually requires a fixative (see below). Charcoal is also harder to erase than graphite

Artist's charcoal comes in a variety of forms. The most popular charcoal tools are compressed charcoal sticks. With charcoal sticks, the artist can produce both lines (with the tip) and areas of value (with the side). Charcoal-leaded pencils can also be purchased.

Vine charcoal is a piece of plant that has been turned to charcoal but has not been pulverized and compressed. Vine charcoal can be held like a pencil or broken and used like charcoal sticks. Since it has not been compressed, it tends to produce a lighter mark than compressed charcoal.

Some artists prefer to use charcoal powder applied directly to the art surface and manipulated with fingers or brush. Charcoal or graphite powder can also be placed in a small fabric bag which is then rubbed against the art surface; this produces a subtle shading effect that can be smoothly varied across the page.

Smudging tools are used to move pigment around on the drawing surface, blending or smearing it. The simplest smudging tool is the finger, although care should be used not to damage the artwork with the oils from hands. Cheap (lotion-free!) toilet paper, facial tissues, and Q-Tips can all be used as smudging tools.

Blending stumps (also known as "tortillons" or "smudge sticks") are lengths of tightly rolled paper that come to a point at one or both ends. Stumps are useful because they allow for precise blending, by using either the flat or tip of the point. After a stump has built up an amount of graphite or charcoal on its point, it can be used as a drawing tool in its own right; the light strokes it produces can be useful when first roughing out a piece.

Dip pens are pens with no internal ink reservoir; the ink is held in the nib at the tip of the pen, so the pen needs to be dipped in an external ink supply regularly to refresh the ink supply. Dip pens consist of a nib holder and a nib. Nibs wear out with time and need to be replaced. Different nibs produce different sizes and shapes of pen strokes. The "crow's quill" type of nib is frequently used in illustration, since the width of the line it produces can be varied by altering the pressure applied to the paper during the stroke.

Disposable pens come with an internal ink reservoir that is non-replaceable, while cartridge pens have a replaceable ink reservoir. Care must be taken in selecting pens for art-making, since many are intended for writing and do not use archival quality ink -- that is, the marks they produce may fade, change color, or alter the paper over time. Most technical pens are of archival quality.